The present invention relates to a process for treating molten iron with pure magnesium and, more particularly, a process for treating molten iron wherein a granular mixture comprising a granular refractory material and granular magnesium is positioned in a ladle and molten iron is fed to the ladle in a controlled manner so as to substantially eliminate the production of eddies.
There are many known processes wherein granules containing magnesium are mixed with other components and then contacted by molten iron. A typical known process is referred to as the "sandwich" process. Thus, it is known for magnesium granules to be mixed with steel turnings or other abrasives and thereafter contacted with molten iron in an open ladle. The reaction of the magnesium with the melt is controlled by the fact that the melt must first fuse the steel turnings or particles in order to establish a controlled availability of the magnesium granules for reaction with the iron melt. The disadvantage associated with such a process is that the melt cools down during the time period of the process. In order to compensate for this cooling, the iron melt must be charged at a very high temperature to the "sandwich" ladle which involves high melting costs and, as a result of the initial high temperature of the iron melt, a poorer yield of magnesium.
In another known process, magnesium granules are mixed with so-called modifiers, for example, calcium carbide, sand, graphite and the like, in order to delay the reaction between the magnesium and the melt in order to achieve controlled availability of magnesium for reaction with the iron melt. In practice, it has been found that this particular process does not always proceed correctly as it is difficult to control the process from proceeding too fast, that is, making magnesium available at a rate higher than desired. As a result, difficulties arise with such a process.
Naturally, it would be highly desirable to develop a process for treating molten iron with pure magnesium wherein the magnesium is exposed to the iron melt in a controlled manner thereby maximizing magnesium absorption while at the same time controlling reaction parameters.
Accordingly, it is the principal object of the present invention to provide a process for treating molten iron with pure magnesium wherein magnesium is introduced into the iron melt in a controlled manner.
It is a further object of the present invention to provide a process as set forth above wherein the reaction proceeds in a controlled manner without the requirement of providing high heat input.
Further objects and advantages of the present invention will appear hereinbelow.